One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when it's the best time to plant kale in Zone 4b by referring to the USDA zone info.

Planting Calendar for Kale

Frost tolerance for kale:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Kale tend to make it in moderate cold which means that you can plant them just a bit earlier in the year than more sensitive plants.

The earliest that you can plant kale in Zone 4b is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant kale and expect a good harvest is probably August. You probably don't want to wait any later than that or else your kale may not have a chance to grow to maturity. Starting your kale indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Zone 4b the average date of last frost happens on May 15. You can expect an average low temperature of -25°F in the coldest months of winter.

Since the USDA zone info for Zone 4b is just an average the actual date of last frost changes from year to year. Half of the time in Zone 4b last frost occurs after May 15 so make sure that you are ready to protect your kale if you have one of those late frosts.

USDA Zone Info for Zone 4b

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Zone 4b

You may be interested in your other planting guides for Zone 4b.